visualn-8.x-1.x-dev/modules/visualn_block/visualn_block.services.yml

services:
  visualn_block.iframe_content_provider:
    class: Drupal\visualn_block\IFrameContent\BlockIFrameContentProvider
    arguments: ['@plugin.manager.visualn.drawing_fetcher']
    tags:
      - { name: visualn_iframe_content_provider }